Reamer



Jam 28, 3936. J. W. M CLATCHIE REAMER Filed Feb. 5, 1934 INVENTOR. JOHNW MACCLATCHIE ATTORNEY.

Patented Jan. 28, 1936 srArs arcane FATENT OFFICE 14 Claims.

This invention is a rotary reamer for wells, and has for its object toenlarge a well bore to uniform gauge by means of a shearing cuttingaction rather than a mere scraping or swedging action, with the cuttingcontact at a plurality of arcuate areas circumferentially spaced aroundthe tool and combining to provide a cutting engagement throughout anappreciable arc of the circumference of the well bore, and each circum-10, ferentially successive cutting area longitudinally overlapping andprojecting below the preceding cutting area. The entire circumference ofthe well bore may thus be uniformly enlarged, with the uniformenlargement continuous along the length of the well bore.

It is a further object of the invention to provide a cutting contactthroughout an appreciable arc of the circumference of the well bore, butto so circumferentially space the areas of contact as to providelongitudinal channels therebetween of such area as to permit freepassage of cuttings without liability of clogging the tool.

It is a still further object of the invention to provide a shearingcutting action as described, by means of an extremely simple and sturdycutter element adapted for convenient assembly and replacement in astring of usual rotary drill pipe.

Further objects of the invention will be readily understood from thefollowing description of the accompanying drawing, in which:

Fig. l is a side elevation of the reamer, partly in axial section.

Fig. 2 is a transverse section on the line 22 of Fig. 1.

Fig. 3 is a diagrammatic illustration of circumferentially successiveteeth of trailing cutters of the cutter element, showing the relativevertical position of the teeth.

The cutter element is preferably an integral structure adapted forconvenient assembly and replacement in a string of rotary drill pipe I;and for this purpose the cutter element is shown as a sleeve 2 adaptedfor sliding reception on a mandrel 3, with the lower end of the mandreladapted for threaded connection with a lower portion of the string ofdrill pipe as shown at 4, and the upper end of the mandrel adapted forthreaded engagement with a sub 5 as shown at 6, and the sub 5 connectedto an upper portion of so the string of drill pipe by a threadedconnection 7. Acirculation bore 8 extends through the mandrel and thesub, and communicates with the usual circulation bore of the string ofdrill pipe.

The sleeve 2 may be held against rotation on the mandrel by a tongue andgroove connection 9 between the lower end of the sleeve and an annularshoulder ill of the mandrel, and the lower end of sub 5 may form anannular abutment H adapted to engage the upper end of sleeve 2 forreleasably locking it against longitudinal dis placement on the mandrel.

A plurality of cutting teeth project radially from sleeve 2, and arepreferably integral with the sleeve so as to provide a simple but sturdyconstruction. The plurality of teeth are adapted to engage the wall ofthe well bore for enlarging it to gauge both throughout itscircumference and along the length of the bore; and for this purpose theteeth are circumferentially spaced around the sleeve 2 so that theircombined cutting contact constitutes an appreciable arc of thecircumference of the well bore, and each circumferentially successivetooth longitudinally overlaps and projects below the next precedingtooth.

As an instance of this arrangement vertical rows of cutters l5 projectradially from the sleeve 2, the rows being equi-distantlycircumferentially spaced and in the illustrated embodiment being shownas three in number. The cutters of each row are vertically spaced fromone another, and the outer peripheries E6 of the cutters are curvedconcentric with the axis of the tool as shown at Fig. 2, so as tomaintain contact with the wall of the well bore along thecircumferential length of the cutters. The cutters are of appreciablecircumferential length so that their combined cutting contact with thewall of the well bore constitutes an appreciable arc of itscircumference, shown in the present instance as nearly one-half thecircumference of the well bore. By the construction as describedvertical channels H are formed between the rows of cutters, and are of across-sectional area providing for passage of cuttings without liabilityof clogging the channels.

The cutters of each vertical row are ofiset longitudinally of the toolrelative to the cutters of the other rows as shown at Fig. 1, with thevertical space between adjacent cutters of any one row equi-distantlydivided by the cutters of the other rows; and the leading end N3 of eachcutter of a row projects below the trailing end IQ of the verticallynext adjacent cutter of that row of cutters which is next in advance inthe direction of rotation of the tool, the direction of rotation beingindicated by the arrow A at Fig. 1.

The cutters are adapted not for a mere swedging or scraping actionforcing the formation radially outwardly to enlarge the bore, but areadapted to actually cut away the formation by a shearing action. Forthis purpose the under surface of cutter i5 slants upwardly toward theaxis of the tool as shown at 2t, and the peripheral edge ill of thecutter slants downwardly from its leading end l8 to its trailing end l9as shown at Fig. 1. The outer surface of the cutter slants radiallyinwardly and upwardly from the peripheral edge It toward the axis of thetool and may merge into the upper surface of the cutter which may inturn continue said slant so as to merge into the peripheral wall ofsleeve 2. It will thus be seen that the cutter does not have a bluntsurface contact with the formation, but that the slanting peripheraledge I6 is a relatively sharp cutting edge adapted for shearing out intothe formation.

The cutting edge it preferably has a cutting point at its leading endfor initiating a shearing cut into the formation, and for this purposethe leading end is of the cutter preferably slants radially outwardlytoward the leading end of cutting edge It as shown at Fig. 2, and theouter and upper surfaces of the cutter in addition to slantingdownwardly and outwardly. radially of the tool mag-"slant downwardlycircumferentially of the tool and toward the leading end of cutting edgeI6 as shown at 23 (Fig. 3), and the leading end I8 of thecutterpreferably slants upwardly and back toward the trailing end of thecutter from the lower edge of said leading end as shown at Fig. 1, inorder to form a distinct cutting point 24 at the leading end of thecutter.

In order to maintain the shearing cut as initiated by the cutting point24, the cutter preferahly has additional cutting points spacedrearwardly from the cutting point 24 along the circumferential length ofthe cutting edge It; and for this purpose the cutter has. verticalgrooves 25 in its outer face, of a depth somewhat less than the radialwidth of the cutter and spaced along the circumferential length of thecutter. Each cutter is thus divided into a plurality of teeth comprisinga leading tooth 26 and a plurality of successively trailing teeth 26with the cutting edge is divided into a plurality of separate cuttingedges Hi for the respective teeth 26-26. The plurality of cutting edges56 define the general downward slant of cutting edge l6 toward thetrailing end i9 of the cutter, but these cutting edges it are preferablysubstantially parallel and are inclined slightly to the general slant ofcutting edge it as shown at Fig. 1, so that the leading end it of eachof the trailing teeth 25 extends below the trailing end Is of thepreceding tooth. The leading ends i8 of the trailing teeth preferablyslant radially outwardly toward the leading ends of their cutting edgesw as shown at Fig. 2, and the outer and upper surfaces of the trailingteeth may slant downwardly both radially and circumferentially of thetool and toward the leading ends of their cutting edges ic as shown at23 (Fig. 3), and the leading ends Ill of the trailing teeth preferablyslant upwardly and back toward the trailing ends of said teeth from thelower edges of said leading ends as shown at Fig. 1, in order to formcutting points M at the leading ends of the trailing teeth. Thesuccessively trailing cutting points 24-44 thus project verticallydownwardly one below another sothat they are each adapted to dig intothe formation and initiate a shearing out along their respective cuttingedges 16 without the cutting point of a preceding tooth masking thecutting point of the next trailing tooth.

Any desired number of cutters it may be pro vided in each of thevertical rows of cutters, and a plurality of intermediate cutters ofeach vertical row, shown as cutters B, have a radial width whereby theyare adapted to cut to gauge, and at least the upper cutter of eachvertical row is slightly under gauge as shown at C for guiding the toolduring withdrawal from the well bore, while a plurality of the lowercutters of each vertical row, shown at D, are preferably under gauge andof decreasing radial width toward the lower end of the tool forgradually enlarging the well bore to gauge as the tool is lowered in thewell.

Lugs may project from the sleeve '2 below each row of cutters l5, withthe lugs tapering downwardly and merging into the peripheral surface ofthe sleeve for guiding the tool into a well bore; and these guide lugsare preferably provided with circumferential grooves 3i affording relieffor cuttings for preventing clogging of the col.

If desired cuttings may be washed away by providing downwardly openingports 33 in the wall of mandrel 3, with the sleeve 2 having ports atcommunicating with the ports 33 but preferably. of larger diameter toprevent cutting-out of the ports. A part of the fluid in circulationbore 8 may thus be discharged through the ports which are preferablypositioned in the channels ll between the circumferentially nextadjacent vertical rows of cutters. 1

By arranging the teeth of each cutter circumferentially adjacent oneanother but appreciably circumferentially spacing the respectivevertical rows of cutters, rather than equi-distantly spacing all of theteeth around the circumference of sleeve 2, the teeth are adapted forcontact with the well bore throughout an appreciable arc of itscircumference, but at the same time the vertical channels l1 between thecircumferentially next adjacent rows of cutters are not so restrictedas'to be liable to clog, but are of appreciable area for free passage ofcuttings; and by arranging the teeth so that each tooth has a '1 cuttingpoint projecting below the trailing end of the preceding tooth, eachcutting point is adapted to dig into the formation, with its slantingcutting edge It then shearing away the formation, and the plurality ofteeth making a continuous shearing cut around the entire circumferenceof the well bore and along an appreciable length of the bore.

I claim:

1. In a rotatable well reamer, a plurality of radially projectingcutting teeth relatively spaced around the entire circumference of thereamer, the end'of each tooth which is its leading end with relation tothe direction of rotation of the reamer extending below the trailing endof the next preceding tooth, and the lower faces of the teeth slantingdownwardly circlnnferentially of the reamer and toward the trailing endsof the teeth.

2. A rotatable well reamer having a radially projecting cutting tooth,the lower face of the tooth slanting downwardly circumferentially oi thereamer and toward the trailing end of the tooth and also slantingdownwardly radially of the tooth to its outer periphery, whereby theouter peripheral lower edge of the tooth forms a relatively sharpshearing cutting edge.

3. A rotatable well reamer having a radially projecting cutting tooth,the leading'end of the tooth with relation to the direction of rotationof the reamer slanting circumferentially forwardly all the way to theouter periphery of the tooth, and the lower face of the tooth slantingdownwardly circumferentially of the reamer and away from the leading endof the tooth, whereby the lower edge of the leading end of the toothforms a relatively sharp cutting point at the outer periphery of thetooth with the lower face of the tooth forming a shearing cuttingsurface extending circumferentially rearwardly from said cutting point.

4. A rotatable well reamer having a radially projecting cutting tooth,the outer face of the tooth slanting radially outwardly and downwardlyall the way to the outer peripheral lower edge of the tooth, and thelower face of the tooth slanting downwardly circumferentially of thereamer and away from the leading end of the tooth, whereby the outerperipheral lower edge of the tooth forms a relatively sharp shearingcutting edge.

5. A rotatable well reamer having a radially projecting cutting tooth,the outer face of the tooth slanting radially outwardly and downwardlyall the way to the outer peripheral lower edge of the tooth, the lowerface of the tooth slanting downwardly radially of the tooth to its outerperiphery, and said lower face of the tooth slanting downwardlycircumferentially of the reamer and away from the leading end of thetooth, whereby the outer peripheral lower edge of the tooth forms arelatively sharp shearing cutting edge.

6. In a rotatable well reamer, a plurality of radially projectingcutting teeth relatively spaced around the entire circumference of thereamer, the end of each tooth which is its leading end with relation tothe direction of rotation of the reamer extending below the trailing endof the next preceding tooth, and the lower faces of the teeth slantingdownwardly radially of the teeth to their outer peripheries.

7. In a rotatable well reamer, a plurality of radially projectingcutting teeth relatively spaced around the entire circumference of thereamer, the end of each tooth which is its leading end with relation tothe direction of rotation of the reamer extending below the trailing endof the next preceding tooth, and the outer and lower faces of the teethslanting downwardly radially of the teeth and meeting at relativelysharp cutting edges at the outer peripheral lower edges of the teeth.

8. In a rotatable well reamer, a plurality of radially projectingcutting teeth relatively spaced around the entire circumference of thereamer, the end of each tooth which is its leading end with relation tothe direction of rotation of the reamer extending below the trailing endof the next preceding tooth, the outer and lower faces of the teethslanting downwardly radially of the teeth and meeting at relativelysharp cutting edges at the outer peripheral lower edges of the teeth,and said cutting edges slanting downwardly circumferentially of thereamer and toward the trailing ends of the teeth, whereby the cuttingedges are adapted for shearing engagement.

9. In a rotatabie well reamer, a plurality of radially projectingcutters appreciably circumferentially spaced from one another and eachcomprising a plurality of cutting teeth with the teeth of each cuttercircumferentially spaced from one another a relatively slight distance,whereby the teeth of the plurality of cutters provide cutting contactthroughout an appreciable arc of a circumference, with channels ofappreciable size between circumferentially next adjacent cutters, thecutter teeth of the plurality of cutters being relatively spaced aroundthe entire circumference of the reamer, with the lower faces of all ofthe teeth slanting downwardly toward their ends which are the trailingends with relation to the direction of rotation of the reamer.

10. In a rotatable well reamer, a plurality of radially projectingcutters appreciably circumferentially spaced from one another and eachcomprising a plurality of cutting teeth with the teeth of each cuttercircumferentially spaced from one another a relatively slight distance,whereby the teeth of the plurality of cutters provide cutting contactthroughout an appreciable are of a circumference, with channels ofappreciable size between circumferentially next adjacent cutters, thecutter teeth of the plurality of cutters being relatively spaced aroundthe entire circumference of the reamer, with the end of each tooth whichis its leading end with relation to the direction of rotation of thereamer below the trailing end of the next preceding tooth.

11. In a rotatable well reamer, a plurality of radially projectingcutting teeth relatively spaced around the entire circumference of thereamer, the lower facesof all of the teeth slanting downwardly towardtheir ends which are the trailing ends with relation to the direction ofrotation of the reamer.

12. A rotatable well reamer having a radially projecting cutting tooth,the lower face of the tooth slanting downwardly circumferentially of thereamer toward the trailing end of the tooth, and the leading end of thetooth slanting upwardly from its lower edge and rearwardly toward thetrailing end of the tooth, whereby the lower edge of the leading end ofthe tooth forms a relatively sharp cutting edge with the lower face ofthe tooth forming a shearing cutting surface extending circumferentiallyrearwardly from said cutting edge.

13. In a rotatable well reamer, a plurality of radially projectingcutting teeth relatively spaced around the entire circumference of thereamer, the end of each tooth which is its leading end with relation tothe direction of rotation of the reamer extending below the trailing endof the next preceding tooth, and the outer face of each tooth slantingradially outwardly and downwardly all the way to the outer peripherallower edge of the tooth so that the teeth form relatively sharp cuttingedges.

14. In a rotatable well reamer, a plurality of radially projectingcutting teeth relatively spaced around the entire circumference of thereamer, the end of each tooth which is its leading end with relation tothe direction of rotation of the reamer extending below the trailing endof the next preceding tooth, and the leading end of each tooth slantingupwardly from its lower edge and rearwardly toward the trailing end ofthe tooth, whereby the lower edges of the leading ends of the teeth formrelatively sharp cutting edges.

JOHN W. MACCLATCHIE.

